Well bailer

ABSTRACT

A plunger for use in well bailers and drilling tools having a plunger mandrel slidably disposed in the body of the bailer and rigid piston rings on the mandrel. The rings have a smaller outside diameter than the inside diameter of the bailer body and a bore through the center of each ring has a larger diameter than the outside diameter of the mandrel, causing the ring to wobble as it moves through the body of the bailer. Grooves are formed around the outer edge of the ring to agitate fluid passing the edge of ring. Fins are formed on the mandrel to minimize rotation of the mandrel relative to the body of the bailer.

United States Patent Primary E.raminerStephen .l. Novosad Atlorneys- Howard E. Moore and Gerald G. Crutsinger ABSTRACT: A plunger for use in well bailers and drilling tools having a plunger mandrel slidably disposed in the body of the bailer and rigid piston rings on the mandrel. The rings have a smaller outside diameter than the inside diameter of the bailer body and a bore through the center of each ring has a larger diameter than the outside diameter of the mandrel, causing the ring to wobble as it moves through the body of the bailer. Grooves are formed around the outer edge of the ring to agitate fluid passing the edge of ring. Fins are formed on the mandrel to minimize rotation of the mandrel relative to the body of the bailer.

WELL BAILElR BACKGROUND OF INVENTION particular location and in which it is desired to reopen or deepen the well to a lower level.

Bailers of the type heretofore utilized in drilling operations employed piston rings or packing elements rigidly secured to a plunger and slidably disposed in sealing engagement with the internal wall of the barrel of the bailer. Sand and other solid particles wedged into the space between the rings and the inner wall of the barrel of the bailer which resulted in scoring and excessive wear on the sealing surfaces.

Percussion tools are lifted a desired distance above an obstruction in the well bore and then dropped to chip away and remove fragments of the obstruction from the bore. The line, comprising a wire rope or cable, is in tension, which imparts a torque to the wire rope, as the tool is raised and lowered. As the body of the tool is dropped into contact with an obstruction in the well bore, the weight of the tool is immediately removed from the wire rope. As the tool moves through gas block areas and drilling fluids of varying densities, the line is stretched and relaxed.

In tools heretofore developed the sudden removal of the weight of the tool body from the wire rope in high tension resulted in violent twisting of the wire rope and spinning of the mandrel and packer rings in the body of the bailer. Any slack or excess length of wire rope which was fed into the well after the instant of contact of the bailer with the obstruction in the well was thrown back up the well bore in the form of a high velocity vibratory wave front in a high tension cord. Such wave front was capable of moving all the way out of the well bore, creating great hazard to workmen around the opening of the well.

SUMMARY OF INVENTION l have developed a plunger for well bailers which has piston rings on the mandrel which have a smaller outside diameter than the inside diameter of the body of the bailer. The mandrel passes through a bore in the piston ring which has a larger diameter than the outside diameter of the mandrel. By providing clearance between the piston rings and the inner wall of the body of the bailer and between the bore through the piston ring and the outer surface of the mandrel, the rigid rings are free to wobble or rock relative to the mandrel and to the body of the well bailer, allowing solid particles which would tend to cause excessive wear on the outer surface of the ring and the inner surface of the body of the bailer to work past the ring.

One or more annular grooves is formed in the outer surface of each ring. The annular groove provides a recess which receives solid particles and also causes agitation of fluid to increase the vacuum drawing capability of the plunger.

Rigid fins, or plates, are rigidly secured to the mandrel to provide hydraulic damping to minimize rotation of the plunger relative to the body of the bailer. The provision of such fins on the plunger causes the fluid in the body of the bailer to absorb much of the energy which is suddenly released from the wire rope as the bailer strikes an obstruction, passes through gas block areas, or through fluid of varying density in the well bore.

It is therefore a primary object of the invention to provide a well bailer having rings slidably disposed in a body adapted to minimize the abrasive action of solid particles between the rings and the body without destroying the vacuum forming capability of the bailer.

Another object of the invention is to provide a well bailer capable of absorbing the potential energy in a stretched wire rope to minimize twisting of the wire rope when the tension thereon is suddenly released or applied.

Another object of the invention is to provide a well bailer which is of simple design and rugged construction capable of withstanding the extreme conditions of wear and hard usage to which percussion apparatus of such character is subjected.

Other and further objects of the invention will become apparent upon referring to the detailed description and drawings annexed hereto.

DESCRIPTION OF DRAWINGS Drawings of a preferred embodiment of the invention is annexed hereto so that the invention may be better and more fully understood, in which:

FIG. I is a partially sectionalized view of the bailer;

FIG. II is a cross-sectional view taken along line Il-ll of FIG. I;

FIG. III is a cross-sectional view taken along line IIIIII of FIG. I; and

FIG. IV is a cross-sectional view taken along line IV-IV of FIG. I.

Numeral references are employed to indicate like parts I throughout the various figures of the drawings.

DESCRIPTION OF A PREFERRED EMBODIMENT In the drawings the numeral 1 generally designates a well bailer having a body comprising a hollow tubular barrel 2, the upper end of which is threadedly connected to a head 4, having a cylindrical bore 6 extending longitudinally therethrough.

The upper tubular stem section 10 of a plunger assembly 8 is slidably disposed through the bore 6 of head 4. The head 4 has a beveled shoulder 12 and a reduced section 14 at the upper end thereof with threads or teeth 16 disposed thereabout to facilitate connecting a fishing tool (not shown) thereto to remove the bailer from a well bore, should it be necessary to do so.

Suitable lowering means, such as wire rope 18, is secured to the upper end of stem section 10 of the plunger assembly 8 and extends upwardly through the well bore to suitable takeup and dispensing means such as the drum of a wench (not shown).

A traveling valve cage 20 is secured to the lower end of stem section 10, said valve cage having a curved shoulder portion 22 on the upper end thereof arranged to enter the beveled lower end 24 of bore 6 which extends through the head 4.

Valve cage 20 has apertures 26 extending through the walls thereof and the lower end of the valve cage is threadedly connected at 28 to the upper end of a hollow tubular mandrel 30. Mandrel 30 has a passage 32 extending longitudinally therethrough, said passage being open at the lower end in fluid communication with bore 60 which extends longitudinally through barrel 2. A valve seat 34 is formed in the upper end of passage 32 and receives valve element 36 to prevent the flow of fluid downwardly through passage 32 when the plunger is moved upwardly.

A suitable impact bit 40, having a cutting edge 42 on the lower end thereof, is threadedly secured at 44 to the lower end of barrel 2 of the bailer body. Apertures 46 and 47 extend through the sidewalls of the bit 40, forming means through which fluid containing solid particles may be drawn into passage 48 in the bit 40. A valve seat 50 extends into passage 48, and a check valve element 52 is associated therewith to allow fluid and cuttings to flow through apertures 46 and 47 upwardly through passage 48 into bore 60 which extends longitudinally through the barrel 2 of the bailer body. However, check valve 52 prevents the flow of fluid downwardly through bore 60 into bore 48 of bit 40.

The mandrel 30 has rings 65 mounted thereon below the lower end of the traveling valve cage 20. Rings 65 are rigid cylindrical elements having a bore 66 extending therethrough.

Referring to F168. 1 and II], it should be noted that bore 66 through ring 65 is of larger diameter than the outside diameter of mandrel 30, thus providing clearance between mandrel 30 and ring 65.

Each ring 65 is restrained from axial movement along mandrel 30 by shoulders 68 and 69 which extend outwardly from mandrel 30 above and below each ring 65. Clearance is also provided between the lower edge of upper shoulder 69 and the upper edge of ring 65 so as not to prevent rocking motion of ring 65 relative to mandrel 30.

The outer circumference of each ring 65 has one or more annular grooves 70 formed thereabout, with lands or ridges 72 extending around the upper and lower edges of each groove 70.

The outside diameter of each land 72 is of smaller diameter than that of bore 60 which extends through the barrel 2 of the body of the bailer. Provision of clearance between the outside edge oflands 72 and the wall 74 of bore 60 allows each ring 65 to tilt or wobble relative to the inner wall 74 of the barrel 2 as the plunger assembly 8 moves vertically relative to the body portion of the bailer.

From the foregoing it should be readily apparent that the rigid rings 65 are restrained from axial movement by shoulders 68 and 69 on mandrel 30 of the plunger assembly 8 and that each ring 65 is free to rock and tilt as the plunger assembly 8 moves through the bore 60 of the body portion of the bailer to prevent wedging of the solid materials between the outer edges of the piston 65 and the wall 74.

Annular grooves 70 in the edges of each rigid ring 65 cause agitation of fluid which flows through the clearance between the outer edges of lands 72 and the inner wall 74 of barrel 2 to increase the vacuum forming capability of plunger 8 as it is drawn upwardly through the bore 60 to draw fluid thereinto.

Fins 80 are welded, or otherwise rigidly secured, to a plurality of locations on the outer walls of the traveling valve cage 20. Fins 82 and 84 are rigidly secured to mandrel 30 between shoulders 68 and 69 and extend outwardly from said mandrel between rigid rings 65. Fins 86 are fixedly secured to the lower end of mandrel 30 below the lowermost ring 65.

Since check valve 52 in hit 40 prevents the flow of fluid downwardly through bore 60, fluid is normally present in said bore. As hereinbefore pointed out the weight of bailer 1 suspended from a long length of wire rope 18 causes the wire rope to stretch resulting in the exertion of a considerable torque on plunger assembly 8 when the weight of the bailer is suddenly removed from wire rope 18 as the lower end of impact bit 40 strikes an obstruction in the well bore. Fins 80, 82, 84 and 86 on the traveling valve cage and the mandrel 30, respectively, provide hydraulic braking action to reduce the tendency of plunger assembly 8 to spin relative to the barrel 2 ofthe bailer body.

It will be seen that when the plunger 8 is lowered in the barrel 2 with the bit on bottom, fluid and cuttings will pass upwardly through passage 32, lifts valve 36 off its seat and allows the fluid to pass outwardly through ports 26 and downward flow of the fluid is prevented through the passage 32 when the plunger is raised in the barrel. Fluid above ring 65 is forced out of the barrel 2 through bore 6. The fins 80, 82 and 84 prevent excessive twisting of cable 18 and spinning of the mandrel when tension is removed from the cable.

From the foregoing it should be readily apparent that l have developed a well bailing tool which accomplishes the objectives hereinbefore enumerated. lt should also be readily apparent that rings 65 and fins 80-86 may be employed in combination with other types of bailer body and cutting bit without departing from the basic concept of my invention.

Having described my invention I claim:

1. In a well bailer the combination comprising, a tubular body having a bore extending longitudinally through a portion thereof; a plunger assembly slidably disposed in said bore, said plunger having a passage formed therein; valve means to control flow through said passage; at least one rigid ring on said plunger assembly; means for attaching the ring to the plunger assembly such that the ring is free to rock relative to the plunger assembly and the tubular body as the plunger assembly moves through the bore in the body.

2. The combination called for in claim 1 with the addition of at least one annular groove formed in the outer edge of the rigid ring.

3. The combination called for in claim 2 wherein the surface adjacent each groove is disposed in spaced apart relation from the inner wall ofthe bore in the tubular body.

4. The combination called for in claim 1 with the addition of means to restrain rotation of the plunger assembly relative to the tubular body.

5. The combination called for in claim 1 with the addition of means to restrain longitudinal movement of the ring on the plunger assembly.

6. The combination called for in claim 1 wherein the means for attaching the ring to the plunger assembly comprises a bore through the rigid ring and a portion of the plunger assembly extends through said bore in the ring, said bore in the ring being larger than the portion of the plunger which extends therethrough and means secured to the plunger assembly above and below the ring to limit movement thereof relative to the plunger.

7. A plunger and piston assembly for a well tool comprising, a mandrel; a piston ring on the mandrel; said ring having a bore extending therethrough which is of larger diameter than the mandrel; means on the mandrel to restrain longitudinal movement of the ring on the mandrel when the mandrel is positioned in the bore, said means being so spaced on the mandrel as to allow the ring to rock on the mandrel; and a plurality of longitudinally extending fins on the mandrel extending outwardly from the surface thereof to retard rotation of the mandrel about its longitudinal axis when the plunger and piston assembly is disposed in fluid.

8. The combination called for in claim 7 wherein the piston ring has an annular groove formed in the outer edge thereof.

9. A plunger and piston assembly for a well tool, the combination, comprising, a tubular body, a mandrel reciprocably movable in the body; suction forming means on the mandrel; and at least one fln on the mandrel arranged to engage fluid in a well tool to retard rotation of the mandrel about its longitudinal axis when the tubular body has fluid therein.

10. The combination called for in claim 9 wherein the suction forming means comprises a piston on the mandrel.

11. A well tool comprising the combination, a tubular body having a bore extending longitudinally therethrough; a cutting tool on the lower end of the body, said cutting tool having a passage therethrough in fluid communication with the bore in the tubular body; control means to regulate the flow of fluid through the said passage; a mandrel slidably disposed in the bore of the tubular body; a piston on the mandrel; means for securing the piston to the mandrel such that the piston is free to rock relative to the bore in the tubular body, said mandrel having a passage in fluid communication with the bore through the tubular body above and below the piston; and check valve means in the passage for controlling fluid flow through said passage.

12. The combination called for in claim 11 with the addition of at least one annular groove about the outer edge of the piston.

13. The combination called for in claim 11 with the addition of means to restrain rotation of the mandrel relative to the tubular body when submerged in fluid.

14. In a well bailer the combination comprising. a tubular body having a bore extending longitudinally through a portion thereof; a plunger assembly slidably disposed in said bore; at least one rigid ring on said plunger assembly; means for attaching the ring to the plunger assembly such that the ring is free to rock relative to the plunger assembly and the tubular body as the plunger assembly moves through the bore in the body; valve means on the plunger; and means attached to the valve means to restrain rotation of the plunger assembly relative to the tubular body.

means for attaching the ring to the plunger assembly such that the ring is free to rock relative to the plunger assembly and the tubular body as the plunger assembly moves through the bore in the body. 

1. In a well bailer the combination comprising, a tubular body having a bore extending longitudinally through a portion thereof; a plunger assembly slidably disposed in said bore, said plunger having a passage formed therein; valve means to control flow through said passage; at least one rigid ring on said plunger assembly; means for attaching the ring to the plunger assembly such that the ring is free to rock relative to the plunger assembly and the tubular body as the plunger assembly moves through the bore in the body.
 2. The combination called for in claim 1 with the addition of at least one annular groove formed in the outer edge of the rigid ring.
 3. The combination called for in claim 2 wherein the surface adjacent each groove is disposed in spaced apart relation from the inner wall of the bore in the tubular body.
 4. The combination called for in claim 1 with the addition of means to restrain rotation of the plunger assembly relative to the tubular body.
 5. The combination called for in claim 1 with the addition of means to restrain longitudinal movement of the ring on the plunger assembly.
 6. The combination called for in claim 1 wherein the means for attaching the ring to the plunger assembly comprises a bore through the rigid ring and a portion of the plunger assembly extends through said bore in the ring, said bore in the ring being larger than the portion of the plunger which extends therethrough and means secured to the plunger assembly above and below the ring to limit movement thereof relative to the plunger.
 7. A plunger and piston assembly for a well tool comprising, a mandrel; a piston ring on the mandrel; said ring having a bore extending therethrough which is of larger diameter than the mandrel; means on the mandrel to restrain longitudinal movement of the ring on the mandrel when the mandrel is positioned in the bore, said means being so spaced on the mandrel as to allow the ring to rock on the mandrel; and a plurality of longitudinally extending fins on the mandrel extending outwardly from the surface thereof to retard rotation of the mandrel about its longitudinal axis when the plunger and piston assembly is disposed in fluid.
 8. The combination called for in claim 7 wherein the piston ring has an annular groove formed in the outer edge thereof.
 9. A plunger and piston assembly for a well tool, the combination, comprising, a tubular body, a mandrel reciprocably movable in the body; suction forming means on the mandrel; and at least one fin on the mandrel arranged to engage fluid in a well tool to retard rotation of the mandrel about its longitudinal axis when the tubular body has fluid therein.
 10. The combination called for in claim 9 wherein the suction forming means comprises a piston on the mandrel.
 11. A well tool comprising the combination, a tubular body having a bore extending longitudinally therethrough; a cutting tool on the lower end of the body, said cutting tool having a passage therethrough in Fluid communication with the bore in the tubular body; control means to regulate the flow of fluid through the said passage; a mandrel slidably disposed in the bore of the tubular body; a piston on the mandrel; means for securing the piston to the mandrel such that the piston is free to rock relative to the bore in the tubular body, said mandrel having a passage in fluid communication with the bore through the tubular body above and below the piston; and check valve means in the passage for controlling fluid flow through said passage.
 12. The combination called for in claim 11 with the addition of at least one annular groove about the outer edge of the piston.
 13. The combination called for in claim 11 with the addition of means to restrain rotation of the mandrel relative to the tubular body when submerged in fluid.
 14. In a well bailer the combination comprising, a tubular body having a bore extending longitudinally through a portion thereof; a plunger assembly slidably disposed in said bore; at least one rigid ring on said plunger assembly; means for attaching the ring to the plunger assembly such that the ring is free to rock relative to the plunger assembly and the tubular body as the plunger assembly moves through the bore in the body; valve means on the plunger; and means attached to the valve means to restrain rotation of the plunger assembly relative to the tubular body.
 15. In a well bailer the combination comprising, a tubular body having a bore extending longitudinally through a portion thereof; a plunger assembly slidably disposed in said bore; at least one longitudinally extending fin on the plunger assembly to restrain rotation of the plunger assembly relative to the tubular body; at least one rigid ring on said plunger assembly; means for attaching the ring to the plunger assembly such that the ring is free to rock relative to the plunger assembly and the tubular body as the plunger assembly moves through the bore in the body. 